Depends on what I'm shooting as to what is in it.
So excludung guns and ammo what I usually have in my range bag is:
electronic hearing muffs, extra cheap pair of regular muffs, a bottle of 50 pairs of disposable foam ear plugs, a stapler to staple targets, extra staples, packs of red and black dots from office depot, (can be used to make targets - just stick one on a sheet of paper or a paper plate, also can use them to cover bullet holes in a siluette or larger target), bandaids and neosporin, a pact shot timer, extra battery for shot timer, decks of playing cards for targets, balloons for targets, three pair of cheap shooting glasses, notebook, pen - usually just have one on me all the time anyway
What I sometimes also have in my range bag:
Chrony, front and rear sand bags and/or front shooting rest for rifle, pistol rest, binoculars (larger or smaller depending on what I'm shooting, belt for holster, various holsters.
I'm probably leaving somethings out - It does get heavy if you add 2 or 3 guns in hard or softsided cases and then ammo and extra magazines. I just bought my first aluminum 4 gun pistol case so I'll be carrying the weight more distributed if I taking more than one or two pistols now. Usually have extra cases to carry anyway if I'm shooting rifles - have five rifle cases - three hard sided and two soft sided that I switch out to carry whatever I'm taking to the range that day - though I rarely would take more than two or three rifles at one time.
I have a separate cleaning case, (a fishing tackle box that has all my cleaning supplies - well not all - extra bottles of cleaner or lubricant I store seperately). I clean when I get home.
I have an extra generic small plastic storage tub that if I have a lot of stuff, extra targets, sand bags, front rest, chrony, pistol rest and so on that I can just throw in the car.
Now my wife just got her first range bag - it has a small cleaning kit, electronic muffs, ear plugs, shooting glasses, extra battery for her red dot, a brick of 22 ammo, lubicant, Hoppes, and extra cleaning patches, with her gun in a hardsided case when she's ready to go.
Okay - now I'm too worn out from toting all this crap to shoot.